Intrapulmonary lymphoid tissue in mink infected with Aleutian disease virus

Pulmonary lymphoid tissue was studied histologically in mink infected experimentally and naturally with Aleutian disease virus, an infection characterised by systemic lymphoid tissue hyperplasia. Lymphoid tissue hyperplasia was observed in the lamina propria of the bronchial tree, in perivascular tissue, in interlobular septae and subpleurally by day 42 after experimental aerosol infection. Four forms of pulmonary lymphoid tissue were recognised: lymphoepithelial nodules or bronchus-associated lymphoid tissue; lymphoid clusters; lymph nodes and diffuse lymphoid tissue. The cel components of these pulmonary reactions were indistinguishable from those seen in the kidney and the liver of the same experimental animals, except for lymphoepithelial nodules which have a specialised association with respiratory epithelium. Pulmonary lymphoid tissue hyperplasia was a significant feature of experimental aerosol infection with Aleutian disease virus but not of natural infections with this virus.